File Coverage

blib/lib/Math/TotalBuilder.pm

Criterion	Covered	Total	%
statement	37	37	100.0
branch	12	12	100.0
condition	2	2	100.0
subroutine	7	7	100.0
pod	3	3	100.0
total	61	61	100.0

use strict;
use warnings;
package Math::TotalBuilder;
{
  $Math::TotalBuilder::VERSION = '1.102';
}
# ABSTRACT: build a whole total out of valued pieces

# aka, solve the bin packing problem lol


use Carp ();

use Exporter 5.57 'import';
our @EXPORT = qw(build total); ## no critic Export


sub build {
	$_[2] ||= \&build_basic;
	if (ref $_[2] eq 'ARRAY') {
		%{(
			sort { $a->{_remainder} <=> $b->{_remainder} }
			map  { { $_->($_[0], $_[1]) } } @{$_[2]}
		)[0]};
	} elsif (ref $_[2] eq 'CODE') {
		return $_[2]->($_[0], $_[1]);
	} else {
		Carp::croak "bad third parameter to build";
	}
}


sub build_basic {
	my ($pieces, $total) = @_;

	return unless $total;

	my %result;

	for (sort { $pieces->{$b} <=> $pieces->{$a} } keys %$pieces) {
		next unless $pieces->{$_} <= $total;
		$result{$_} = int( $total / $pieces->{$_} );
		$total -= $result{$_} * $pieces->{$_};
	}

	$result{_remainder} = $total if $total;

	return %result;
}


sub total {
	my ($pieces, $set) = @_; ## no critic Ambiguous
	my $total;
	for (keys %$set) {
		Carp::croak "invalid unit type: $_" unless exists $pieces->{$_};
		$total += $set->{$_} * $pieces->{$_};
	}
	$total;
}


"Here's your change.";

__END__